Some sites such as Ok Cupid.com, and are free and offer additional paid services in a freemium revenue model.
Sites may offer additional services, such as webcasts, online chat, telephone chat (VOIP), and message boards.
Some sites provide free registration, but may offer services which require a monthly fee.
Other sites depend on advertising for their revenue.
Online dating or Internet dating is a personal introductory system where individuals can find and contact each other over the Internet to arrange a date, usually with the objective of developing a personal, romantic, or sexual relationship.
Online dating services usually provide unmoderated matchmaking over the Internet, through the use of personal computers or cell phones.
Users of an online dating service would usually provide personal information, to enable them to search the service provider's database for other individuals.
Members use criteria other members set, such as age range, gender and location.
Online dating sites use market metaphors to match people.
Match metaphors are conceptual frameworks that allow individuals to make sense of new concepts by drawing upon familiar experiences and frame-works.